Reference 7277
Lahoud, R G; Lobmeyer, D H; Whitfield, M S (1984) Water-Resources Investigations - U. S. Geological Survey, Report: WRI 84-4253, 49 pp., 1984
| Authors | Lahoud, R G; Lobmeyer, D H; Whitfield, M S |
|---|---|
| Year | 1984 |
| Source | Water-Resources Investigations - U. S. Geological Survey, Report: WRI 84-4253, 49 pp., 1984 |
| ISSN | 0092-332X |
| GeoRef | 1985-031059 |
| Keywords | absolute age; aquifers; ash-flow tuff; Bullfrog Member; C-14; carbon; Cenozoic; Crater Flat Tuff; environmental geology; fractures; ground water; high-level waste; hydraulic conductivity; hydrochemistry; igneous rocks; interpretation; isotopes; Miocene; Neogene; Nevada; Nevada Test Site; Nye County Nevada; permeability; pump tests; pyroclastics; radioactive isotopes; radioactive waste; site exploration; surveys; Tertiary; Tram Member; tuff; United States; USGS; volcanic rocks; waste disposal; well-logging; Yucca Mountain |
Abstract
The well penetrated almost 46 meters of alluvium and 1,174 meters of Tertiary volcanic tuffs. The composite hydraulic head for aquifers penetrated by the well was 728.9 meters above sea level (471.4 meters below land surface), with a slight decrease in hydraulic head with depth. Average hydraulic conductivities ranged from less than 0.001 meter per day for the Tram Member of the Crater Flat Tuff to 1.1 meters per day for the overlying Bullfrog Member of the Crater Flat Tuff. Small values for the Tram Member represented matrix permeability of unfractured rock; large values near the lower part of the Bullfrog Member were associated with the basal bedded or reworked tuffaceous beds, but probably resulted from fracture permeability. Large hydraulic conductivities of the rhyolitic tuffs of Calico Hills, the Prow Pass Member at the top of the Crater Flat Tuff, and the middle of the Bullfrog Member probably resulted from fracture permeability in the ash-flow tuffs. Chemical analyses indicated that the water is a soft sodium bicarbonate type, slightly alkaline, with large concentrations of dissolved silica and sulfate. Uncorrected carbon-14 age dates of the water were 14,100 and 13,400 years.--Modified author abstract.
7 samples from this reference
| Sample | Rock name | Major | Trace | Isotope |
|---|---|---|---|---|
| UE25B1H-2832 | Pyroclastic-fall | yes | yes | |
| UE25B1H-2879 | Pyroclastic-flow | yes | yes | |
| UE25B1H-3393 | yes | yes | ||
| UE25B1H-3602 | yes | yes | ||
| UE25B1H-3767 | yes | yes | ||
| UE25B1H-3835 | yes | yes | ||
| UE25B1H-3963 | Pyroclastic-flow | yes | yes |